/Engine/Source/Editor/AnimGraph/Public/AnimBlueprintExtension.h
Request an anim blueprint extension for an anim blueprint. It is illegal to perform this operation once compilation has commenced, use GetExtension instead.
template<typename ExtensionType> static ExtensionType * RequestExtension ( [UAnimBlueprint](API\Runtime\Engine\Animation\UAnimBlueprint) * InAnimBlueprint )